/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  ?Description

*

*/

#ifndef __MDEITEM_H__

#define __MDEITEM_H__

#include <e32base.h>

#include <mdccommon.h>

/** 

 * Internal identifier for metadata engine database items. Must always be

 * different from 0.

 */

class CMdESession;

/**

 * Abstract base class for all items stored in the metadata engine database.

 */

NONSHARABLE_CLASS(CMdEItem) : public CBase

	{

public:

	/**

	 * Destructor.

	 */

	virtual ~CMdEItem();

	/* Methods. */

	/**

	 * Returns whether the item belongs to a session.

	 *

	 * @return  <code>ETrue</code>, if the item belongs to a session;

	 *          <code>EFalse</code>, otherwise

	 */

	IMPORT_C TBool BelongsToSession() const;

	/**

	 * Returns the session the item belongs to. Panics if

	 * the item does not belong to any session.

	 *

	 * @return  session that the item belongs to

	 */

	IMPORT_C CMdESession& Session() const;

	/**

	 * Returns whether the item is stored in the database.

	 *

	 * @return  <code>ETrue</code>, if the item is in the database;

	 *          <code>EFalse</code>, otherwise

	 */

	IMPORT_C TBool InDatabase() const;

	/**

	 * Returns the internal database identifier of the item. 

	 *

	 * @return  internal database identifier or <code>KNoId</code> if item is not stored in database.

	 */

	IMPORT_C TItemId Id() const;

	/**

	 * Sets that the internal database identifier of the object.

	 *

	 * @param aId  internal database identifier

	 */

	void SetId(TItemId aId);

	/**

	 * Sets the session the item belongs to. 

	 *

	 * @param aSession  session

	 */

	void SetSession(CMdESession& aSession);

protected:

	/* Constructors and destructor. */

	/**

	 * Constructor. Note that if the new item is in the database

	 * (i.e., it has an internal database identifier), it must also belong 

	 * to a session.

	 *

	 * @param aSession  session that the new item belongs to;

	 *                  or 0, if the new item does not belong to any session

	 * @param aId		internal database identifier of the new item,

	 *                  if the item is in the database (note that then also 

	 *                  <code>aSession</code> must be different from 0);

	 *					or 0, if the item is not in the database

	 */

	CMdEItem(CMdESession* aSession, TItemId aId);

	/**

	 * Second-phase constructor.

	 */

	void ItemBaseConstruct();

	/* Utility methods. */

	/**

	 * Panics if the item does not belong to any session.

	 */

	void CheckSession() const;

private:

	/** Session. */

	CMdESession* iSession;

	/** Internal database identifier. */

	TItemId iId;

	friend class CMdESession;

	};

#endif  // __MDEITEM_H__